Successively depressible alternating switch



July 31, 1962 Flai )6b R. K` WALKER SUCCESSIVELY DEPRESSIBLE ALTERNATING SWITCH Filed May 3, 1961 IOQ.

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INVENTOR. K WALKER United States Patent O 3,047,698 SUCCESSIVELY DEPRESSIBLE ALTERNATING SWITCH Richard K. Walker, Convent, NJ., assignor to McGraw- Edison Company, Elgin, Ill., a corporation of Delaware Filed May 3, 1961, Ser.v No. 107,449 4 Claims. (Cl. 20G- 153) This invention relates to an improved switch device adapted especially for starting and stopping dictation transcribing machines, and more particularly it relates to an improved form of successively depressible alternating switch having a push button which when successively depressed shifts the switch mechanism alternately between on and oit positions.

`Such switch devices are mounted typically at the front of the space bar on a typewriter in reach of the thumb of the hand while the fingers are in position on the keyboard. Upon the typist pressing the switch push button the machine is started Vand upon successively pushing the button the machine is stopped, etc.

Objects of the invention are to provide an improved form of such switch device which has a positive snap action responsive to each depression of the manual push button, which is of an improved and simplified construction and which is dependable over long periods of operation.

Other objects and features of the invention will be apparent from the following description and the appended claims.

In the description of the invention, reference is had to the accompanying drawings, of which:

FIGURE 1 is a front elevation of the present switch device with parts in section on the line 1-1 of FIG- URE 2;

FIGURE 2 is a vertical section on the line 22 of FIGURE l; l.

FIGURE 3 is a view similar to FIGURE 1 but showing the switch mechanism in its other position;

FIGURE 4 is a fractional view showing the switch mechanism in a partially operated position from the position it has in FIGURE l;

FIGURE 5 is a fractional section on the line S-S of FIGURE 4; and

FIGURE 6 is a perspective View of the rocker element of the switch mechanism.

The present switch device comprises a housing 10 having a rectangular opening 10a in the top through which projects a manual push button 11. The push button is hinged at the back and stands normally in an upwardly inclined position as shown. In the housing is a frame 12 comprising an insulating base 12a and an upstanding metal back wall 12b having turned over apertured ears 13 at the top supporting a cross pin 14 on which the push button is pi'voted. A torsion spring 15 on the cross pin 14 normally holds the push button in its upper unoperated position.

U bracket 16 is mounted on the base 12a and has one upstanding wall 16a closely adjacent -to the back wall 12b and another upstanding wall 16b about midway the front and back walls of the housing. Mounted on the base in an insulating stack 17 at the front of the intermediate wall 1Gb is a pair of laterally extending, normally closed cantilever mounted contact arms 18 the lower one 18a of which extends beyond the upper one and has an insulating button 19 secured to the free end thereof. Extending transversally through apertures in the top portion of the `U bracket 16 is a pivot pin 20 at right angles to the hinge axis of the manual push button 11. A U-shaped rocker 21 has the back side member 21a thereof staked rigidly to the forward end portion of the pivot pin and has ICC the front parallel side member 2lb thereof provided with an extending finger 22 operable against the switch button 19 to open the switch 18. The back side member 21a of the rocker has a turned over lip 23 the end portions of which abut against the top edge of the intermediate wall 16h to limit the rocker to an angular range of yabout A toggle spring 24 has two tails extending ofi in a V arrangement which are pivoted at their ends respectively to a stud 25 on the intermediate wall 16b and a stud 26 on the finger 22. This toggle spring is of an expanding type which serves as an over-center spring for the rocker 21 to cause the rocker always to seek its respective end position when moved over center.

A coupling is provided between the manual push button 11 and the rocker 21 in the form of a slide plate 27 having a rolled-over edge at the `top which slidably and pivotally embraces a cross pin 28 mounted on the free end portion of the manual push button 11 parallel to its hinge axis. The slide plate is of 'a V shape having a stud pin 29 staked to the lower end portion thereof which slidably engages a slot 30 provided in the front side member 2lb of the rocker. This slot extends through the axis of the pivot pin 20 about equal distances in opposite directions therefrom. are notches 31a and 31h.

In response to the upward biasing of the manual push button 11 the slide plate 27 is held normally in an end position wherein the stud pin 29 engages the end of the slot 30 and holds the rocker 21 in an end position with the slot 30 standing at about 45 with the vertical. Say this initial position of the rocker 21 is its counterclockwise position shown in FIGURE 1 wherein it holds the switch 18 open. Upon depressing the vmanual push button 11 the stud pin 29 engages the notch 31a and shifts the rocker 21 over center in a clockwise direction. This clockwise movement of the rocker over center closes the switch 18. Upon next releasing the manual push button 11 the slide plate 27 is cammed to the left by the stud pin 29 riding up the obliquely positioned slot 30 and coming to rest with the stud pin engaging the left end of the slot. Upon next depressing the manual push button 11 the stud pin 29 rst engages the other notch 3117 and turns the rocker over center in a counterclockwise direction to cause the finger 22 to come to ybear against the switch button 19 and again hold the switch open. Upon now releasing the push button 11 the slide plate is camrned to the right until the stud pin 29 yagain engages the right end of the notch 31. When the manual push button 11 is again depressed the stud pin will next engage the notch 31a and turn the rocker clockwise over center again to close the switch 18 as before-described. Thus, upon successively pressing the manual push button 11 the switch 18 is alternated between its open and closed position. A feature of the present Construction is that in each such operation of the switch device there is a positive over center action. To the operator there is `a hard spot in the central portion of each downward depression of the push button which is followed by a released snap movement to provide a positive feel as to when the switch is operated. The invention provides therefore not only a simple and positively acting -switch device but one which is also normally operated in `a positive manner by the user to provide a positive and dependable switch oper-ation,

The particular embodiment of my invention herein shown and described is intended to be illustrative and not necessarily limitative of the invention, since the same is subject to changes and modifications without departure from the scope of my invention which I endeavor to express according to the following claims.

I claim:

1. A successively depressible alternating switch device In the lower edge of the slot at the ends thereofk for a dictation transcribing machine comprising a manually operable push button biased into an unoperated position, an electrical switch, a pivoted rocker, means biasing said rocker over-center into one position wherein it bears against said switch to hold it in one position `and into a second position wherein it is free of said switch and the switch assumes its other position, a guide slot in said rocker on a diameter line of the pivot axis thereof, limit stops for said rocker limiting the movement thereof t0 one end position wherein said slot is oblique in a clockwise direction to the direction of movement of said manual push button and -to a second end position wherein said slot is oblique in ya counterclockwise direction to the direction of movement of said push button, said slot having notches at the ends thereof in the edges -at the far side from said push button, and a slide member on said push button having a pin engaging said slot for holding said slide member in an end position to engage one of said notches and shift said rocker over center in one direction `as the manual push button is depressed and for camming said slide to its other end position upon release ofthe push button to place said pin in position to engage the other of said notches and shift said rocker over center in the other direction as said push button is again depressed whereby successive depressions of said manual push button cause said switch to be shifted alternately between open and closed positions.

2. The switch device set forth in claim 1 wherein said manual push button is pivotally mounted along one edge thereof, said rocker is pivotally mounted on an axis transverse to the pivot axis of said manual push button, and said slide member is mounted on said push button for movement in directions parallel to the pivot axis of the push button.

3. The switch device set forth in claim l wherein said electrical switch is biased closed and is held open by the over-center biasing force exerted on said rocker when the rocker is in its end position engaging said switch.

4. A successively depressible alternating switch device for a dictators transcribing machine comprising a frame having a base, an upstanding side wall and an upstanding intermediate wall parallel to the side wall, an electrical switch, means mounting said switch on said base for actuation in directions normal thereto, a rocker pivoted to said intermediate wall on an -axis normal thereto for movement against said switch to operate the same, means biasing said rocker over center between switch operating and non-operating positions, a manual push button hinged Ito said sidewall and biased into an upward unoperated position, a crosspin on the free end portion of said manual push button, a coupling member movable slidably and pivotally on said crosspin in directions parallel to the hinge axis of the manual push button, said rocker having a slot crosswise to the pivot axis thereof provided with notches at the ends thereof in the edges of the slot remote from the manual push button, and a pin on said coupling member engaging said slot and responsive to the overcenter biasing of said rocker and the upward biasing of said manual push button for causing said coupling member to be held normally in an end position wherein upon depressing said manual push button said pin engages the adjacent notch in said slot and turns said rocker over center `to its other position and wherein upon releasing said manual push button said coupling member is oammed to its other end position for engaging the other notch in `said rocker and turning the rocker over center in the other direction when said manual push button is again pressed.

References Cited in the tile of this patent UNITED STATES PATENTS 2,042,369 Von Kilian May 26, 1936 2,708,371 Pashby May 17, 1955 2,769,050 Bourne Oct. 30, 1956 

